I have recently made a succesful conversion of an iMac DV 400 to make it 600MHZ with 16MB VRAM. Anyway since I have done the conversion, the power light on the front stays orange and is very faint. Also the first time I booted the machine the screen was all f***** up, this has just disappeared and now it works perfecly fine except for the power LED. Any ideas as to what is causing this?

Not sure whats up with that. Maybe it is a power issue. You are running a high OC. Try backing the speeddown and see if that changes it. By the way, please watch you language, we have many younger readers andpeople who are uncomfortable with the F bomb. Thanks.-maestro

The 600s had a different power supply to the 400s. The one I tried swapping wouldn't even boot. I would say TCP is spot on with his estimate of straining the PSU.What you choose to do about it is up to you, but if you don't have the PSU form the 600 or its dead, or you simply don't wish to swap it as they are a pain to swap (Not to mention dangerous) then an ATX conversion would seem to be the easiest fix. If not the most elegant.

an ATX conversion would seem to be the easiest fix. If not the most elegant.

Do you mean putting the mobo in an ATX case? I'd prefer to keep my iMac the way it is. Plus it works better than ever with the new mobo, so unless there's some kind of danger that me or my mac are in at the moment I don't see the point of another mod.

Its quite simple really. The PSU on the 400MHz is built to run a 400MHz chip and its various ancillaries. A 600MHz chip (if it is the same chip, which it is), will use more power than a 400MHz chip. Like I say when I tried it, it wouldn't even power on, and we have established that your PSU is very likely to be under more strain than it was designed for.

This is not unlike overclocking your PSU. It may well be fine. Or it may not work (as in my case).If it does work it will almost certainly shorten the life of the PSU, and these are the weak point on G3 iMacs anyway.If the PSU fails, it may do so without event. Or it may melt. Or it may explode. Or catch fire. I'm not trying to worry you, this is unlikely to happen.

But its best to get into good habits. I would do something about the PSU if I were you.I wonder if you could fit a 1U ATX PSU into the bottom of the iMac case...... That would be quite original. I've never seen it done.

it may melt. Or it may explode. Or catch fire. I'm not trying to worry you, this is unlikely to happen.

But its best to get into good habits. I would do something about the PSU if I were you.I wonder if you could fit a 1U ATX PSU into the bottom of the iMac case...... That would be quite original. I've never seen it done.

You really freaked me out on fire/exploding part. And on the 1U ATX PSU, I really doubt that's a possibility as there's little room down there + cooling won't improve. I might just try to get my hands on an authentic 600MHZ iMac PSU.

By the way, the chip is different. The 400MHz one is a normal PPC750, the 600MHZ one is a PPC750cx. Don't know if there's much difference though...

Anyways thanks for the help and I'll kee you posted (if my mac doesn't explode in my face that is:blink: )

Relax, if it was going to explode, it probably would have by now. Just keep an eye on the temperature. If the case is getting too warm, shut it down for a bit. Perhaps avoid leaving it running for long periods or while you're out of the house.

Even if it fails, it will probably just stop running. Don't panic, just show it some respect until you get to trust it. If it stays pretty cool, its probably fine.

Xplain's use of MacNews, AppleCentral and AppleExpo are not affiliated with Apple, Inc. MacTech is a registered trademark of Xplain Corporation. AppleCentral, MacNews, Xplain, "The journal of Apple technology", Apple Expo, Explain It, MacDev, MacDev-1, THINK Reference, NetProfessional, MacTech Central, MacTech Domains, MacForge, and the MacTutorMan are trademarks or service marks of Xplain Corp. Sprocket is a registered trademark of eSprocket Corp. Other trademarks and copyrights appearing in this printing or software remain the property of their respective holders.

All contents are Copyright 1984-2010 by Xplain Corporation. All rights reserved. Theme designed by Icreon.